Esters and amides of aminomethylenecyanoacetic acid a cosmetic preparation containing the same as a sunscreen agent and a method for protecting human skin using the same

ABSTRACT

PCT No. PCT/EP92/01432 Sec. 371 Date Jan. 5, 1994 Sec. 102(e) Date Jan. 5, 1994 PCT Filed Jun. 25, 1992 PCT Pub. No. WO93/01164 PCT Pub. Date Jan. 21, 1993.Esters and amides of aminomethylenecyanoacetic acid I     &lt;IMAGE&gt;  (I)  where R1 and R2 are each, independently of one another, phenyl, naphthyl, biphenylyl or five- or six-membered hetaryl with one, two or three nitrogens or one oxygen or one sulfur or one nitrogen and one oxygen or one nitrogen and one sulfur, which can be benzo-fused, it being possible for these radicals to be substituted by one to three C1-C12-alkyl groups, C1-C12-alkoxy groups, halogen atoms, cyano groups, hydroxyl groups or groups of the formulae COOR3, COR3, CONHR3, OCOR3 or NHCOR3, and where R3 is C1-C12-alkyl, C5-C8-cycloalkyl or phenyl, X is C2-C30-alkylene which can be interrupted by non-adjacent oxygens, or is C4-C12-alkenylene or C4-C12-alkynylene where the unsaturated bonds are not adjacent to the ester oxygens, or is C5-C8-cycloalkylene or phenylene, and Y is O or NH. are used as stabilizers for organic materials.

This application is a 371 of PCT/EP92/01432 filed on Jun. 25, 1992.

The present invention relates to novel esters and amides of aminomethylenecyanoacetic acid of the formula I ##STR2## where R¹ and R² are each, independently of one another, phenyl, naphthyl, biphenylyl or five- or six-membered hetaryl with one, two or three nitrogens or one oxygen or one sulfur or one nitrogen and one oxygen or one nitrogen and one sulfur, which can be benzo-fused, it being possible for these radicals to be substituted by one to three C₁ -C₁₂ -alkyl groups, C₁ -C₁₂ -alkoxy groups, halogen atoms, cyano groups, hydroxyl groups or groups of the formulae COOR³, COR³, CONHR³, OCOR³ or NHCOR³, and where

R³ is C₁ -C₁₂ -alkyl, C₅ -C₈ -cycloalkyl or phenyl,

X is C₂ -C₃₀ -alkylene which can be interrupted by non-adjacent oxygens, or is C₄ -C₁₂ -alkenylene or C₄ -C₁₂ -alkynylene where the unsaturated bonds are not adjacent to the ester oxygens, or is C₅ -C₈ -cycloalkylene or phenylene, and

Y is O or NH.

The present invention also relates to a process for preparing the compounds I and to organic materials containing the compounds I and thus stabilized against the action of light, oxygen and heat, especially stabilized plastics and surface coatings, and to cosmetic preparations containing the compounds I as sunscreen agents.

Organic materials, especially plastics and surface coatings, are known to be very rapidly decomposed in particular by the action of light. This decomposition is normally manifested by yellowing, discoloration, fissuring or embrittlement of the material. No satisfactory protection against decomposition of organic material by light, oxygen and heat has been achieved with the stabilizers used to date.

Thus, for example, U.S. Pat. No. 3,079,366 recommends, inter alia, arylaminoethylenes of the formula III ##STR3## as UV absorbers for plastics. Although the compounds III have the required spectroscopic properties, they do not meet current requirements in terms of their stabilizing action. In particular, the tendency of plastics stabilized with the compounds III to be come yellow is still too great.

It is an object of the present invention to provide stabilizers which effectively protect organic material.

We have found that this object is achieved by the esters and amides of aminomethylenecyanoacetic acid I defined in the first paragraph.

Examples of suitable hetaryl radicals R¹ and R² are those derived from pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, pyridine, pyridazine, pyrimidine, pyrazine, 1,2,3-triazine, 1,2,4-triazine, 1,2,3-triazine, furan, thiophene, oxazole, isoxazole, thiazole, indole, benzofuran, benzothiophene, benzimidazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline or phthalazine.

Suitable substituents on the ayrl or hetaryl radicals R¹ and R² are:

straight-chain or branched C₁ -C₁₂ -alkyl such as, in particular, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, but also n-pentyl, tert-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, isononyl, n-decyl, isodecyl, n-undecyl or n-dodecyl;

straight-chain or branched C₁ -C₁₂ -alkoxy such as, in particular, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, n-pentoxy and tert-pentoxy, but also n-hexoxy, n-heptoxy, n-octoxy, 2-ethylhexoxy, n-nonoxy, isononoxy, n-decyloxy, isodecyloxy, n-undecyloxy or n-dodecyloxy;

halogen such as, in particular, chlorine, but also fluorine, bromine or iodine;

cyano;

hydroxyl;

groups of the formula COOR³, for example methoxy-carbonyl, ethoxycarbonyl, propoxycarbonyl or butoxycarbonyl;

groups of the formula COR³, for example acetyl or benzoyl;

groups of the formula CONHR³, for example N-methyl-aminocarbonyl, N-ethylaminocarbonyl or N-phenylaminocarbonyl;

groups of the formula OCOR³, for example methoxy-carbonyloxy or ethoxycarbonyloxy;

groups of the formula NHCOR³, for example N-acetylamino, N-propionylamino or N-benzoylamino.

In these groups, R³ is straight-chain or branched C₁ -C₁₂ -alkyl, for which the same examples as indicated above can be given, C₅ -C₈ -cycloalkyl such as, in particular, cyclopentyl and cyclohexyl, but also cycloheptyl, cyclooctyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl or dimethylcyclohexyl, and phenyl.

The number of substituents on the aryl or hetaryl radicals R¹ and R² can be up to 3, preferably up to 2. Where there are several substituents, these can be identical or different.

In a preferred embodiment, R¹ and R² are each, independently of one another, in particular phenyl which can be substituted by one or two C₁ -C₁₂ -alkyl groups, in particular C₁ -C₄ -alkyl groups, C₁ -C₁₂ -alkoxy groups, in particular C₁ -C₅ -alkoxy groups, chlorine atoms, cyano groups, hydroxyl groups or groups of the formula COOR³ where R³ has the abovementioned meanings, but especially C₁ -C₄ -alkyl, cyclopentyl, cyclohexyl or phenyl, but also pyridinyl or 2-pyrimidinyl, each of which can be substituted by one or two C₁ -C₄ -alkyl groups, especially methyl or ethyl.

Suitable bridges X are:

straight-chain or branched C₂ -C₃₀ -alkylene such as 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 1,2-butylene, 2,3-butylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene or dodecamethylene;

C₂ -C₃₀ -alkylene, in particular C₂ -C₁₈ -alkylene, which is interrupted by one or up to 9, in particular one or up to 5, non-adjacent oxygens and is preferably straight-chain or branched to only a small extent;

C₄ -C₁₂ -alkenylene such as 1,4-but-2-enylene, 1,6-hex-3-enylene or 1,8-oct-4-enylene;

C₄ -C₁₂ -alkynylene such as 1,4-but-2-ynylene, 1,6-hex-3-ynylene or 1,8-oct-4-ynylene;

C₅ -C₈ -cycloalkylene such as 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 1,4-cycloheptylene, 1,5-cyclooctylene or ##STR4## o-, m- or, in particular, p-phenylene.

In a preferred embodiment, the bridge X is

C₂ -C₁₂ -alkylene, in particular C₂ -C₆ -alkylene, which is preferably polymethylene;

a polyethylene glycol or polypropylene glycol group of the formula --(CH₂ CH₂ O)_(n) --CH₂ CH₂ -- or ##STR5## where n is 1 to 9, in particular 1 to 5 (the values for n are usually averages);

cis-1,4-but-2-enylene;

1,4-but-2-ynylene;

C₆ -C₈ -cycloalkylene, in particular 1,2-cyclohexylene or 1,4-cyclohexylene or ##STR6## p-phenylene.

The compounds I are advantageously prepared by reacting esters or amides of cyanoacetic acid of the formula II ##STR7## where X and Y have the abovementioned meanings, with 2 equivalents of aromatic or heteroaromatic amines of the formula R¹ --NH₂ or R² --NH₂, where R¹ and R² have the abovementioned meanings, and at least 2 equivalents of a trialkyl orthoformate.

Suitable trialkyl orthoformates are trimethyl orthoformate and, in particular, triethyl orthoformate.

The reaction is expediently carried out in a suitable polar organic solvent such as an alcohol, eg. n-propanol, n-butanol, ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether, cyclohexanol or similar compounds. Also suitable as solvents are carboxamides such as dimethylformamide or excess trialkyl orthoformate. If the starting compounds form a liquid mixture it is possible to dispense with an additional solvent.

The reaction is usually carried out at from 70° to 180° C., preferably 100° to 150° C., under atmospheric pressure. The three reactants are used in the stated stoichiometric or approximately stoichiometric ratio if the trialkyl orthoformate is not also used as solvent; a slight excess of one of the reactants, say up to about 15%, is acceptable.

If the reaction times are very long it is possible to add as catalysts if required Lewis acids such as AlCl₃, ZrCl₄, TiCl₄ or, in particular, ZnCl₂ in the amounts customary for this purpose.

The cyanoacetic esters II can be prepared, for example, by reacting cyanoacetic acid with appropriate diols HO--X--OH in the presence of a catalyst such as boric acid or tetrabutyl orthotitanate, and they are disclosed, for example, in U.S. Pat. No. 4,218,515 and EP-A 136 260.

The esters and amides of aminomethylenecyanoacetic acid I according to the invention are outstandingly suitable as stabilizers of organic material against the action of light, oxygen and heat. They are also effective metal deactivators. They are added to the organic material to be stabilized in a concentration of from 0.01 to 5%, preferably from 0.02 to 2%, of the weight of the organic material, before, during or after its production.

Examples of organic materials are cosmetic products such as ointments and lotions, pharmaceutical formulations such as pills and suppositories, or precursors for plastics and surface coatings, but in particular plastics and surface coatings themselves.

The present invention also relates to organic material, in articular plastics and surface coatings, which is stabilized against the action of light, oxygen and heat and contains the compounds I in the concentrations stated above.

All conventional apparatus and methods for mixing stabilizers or other additives with polymers can be used for mixing the compounds I according to the invention in particular with plastics.

The organic material stabilized by the compounds I according to the invention may contain further additives, eg. antioxidants, light stabilizers, metal deactivators, antistatic agents, flameproofing agents, pigments and fillers.

Examples of antioxidants and light stabilizers which can be used in addition to the compounds according to the invention are compounds based on sterically hindered phenols or sulfur- or phosphorus-containing costabilizers.

Examples of phenolic antioxidants are 2,6-di-tert-butyl-4-methylphenol, n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, tris[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionylethyl] isocyanurate, tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate and pentaerythritol tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

Examples of suitable phosphorus-containing antioxidants are tris(nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(2-tert-butyl-4-methylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite and tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphite.

Examples of suitable sulfur-containing antioxidants are dilauryl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis(β-laurylthiopropionate) and pentaerythritol tetrakis(β-hexylthiopropionate).

Examples of other antioxidants and light stabilizers which can be used together with the compounds I are (2-(2-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones, aryl esters of hydroxybenzoic acids, α-cyanocinnamic acid derivatives, benzimidazolecarboxanilides, nickel compounds or oxalic acid dianilides.

Particularly good stabilization is obtained when at least one light stabilizer from the class of sterically hindered amines is also added in the usual concentration to the compounds I. Examples of suitable sterically hindered amines are bis(2,2,6,6-tetramethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) esters, the condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the condensation product of N,N'-(2,2,6,6-tetramethylpiperidyl) hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethylpiperidyl) nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, 1,1'-(1,2-ethanediyl)bis(3,3,5,5-tetramethylpiperazinone), and the condensation products of 4-amino-2,2,6,6-tetramethylpiperidines and tetramethylolacetylenediureas.

Examples of plastics which can be stabilized by the compounds I according to the invention are:

polymers of mono- and diolefins such as low or high density polyethylene, polypropylene, linear poly-1-butene, polyisoprene, polybutadiene and copolymers of mono- or diolefins or mixtures of said polymers; copolymers of mono- or diolefins with other vinyl monomers such as ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acid copolymers;

polystyrene;

copolymers of styrene or α-methylstyrene with dienes and/or acrylic derivatives such as styrene/butadiene, styrene/acrylonitrile (SAN), styrene/ethyl methacrylate, styrene/butadiene/ethyl acrylate, styrene/acrylonitrile/methacrylate, acrylonitrile/butadiene/styrene (ABS) or methyl methacrylate/butadiene/styrene (MBS);

halogen-containing polymers such as polyvinyl chloride, polyvinyl fluoride, polyvinylidene fluoride and copolymers thereof;

polymers which are derived from α,β-unsaturated acids and derivatives thereof, such as polyacrylates, polymethacrylates, polyacrylamides and polyacrylonitriles;

polymers derived from unsaturated alcohols and amines or the acrylic derivatives or acetals thereof, eg. polyvinyl alcohol and polyvinyl acetate;

polyurethanes, polyamides, polyureas, polyesters, polycarbonates, polysulfones, polyether-sulfones and polyether-ketones.

The compounds I according to the invention can also be used to stabilize surface coatings, eg. industrial coatings. Particularly emphasized among these are stoving enamels, and among these in turn automobile coatings, preferably two-layer coatings.

The compounds I can be added in solid or dissolved form to the coating agent. Their good solubility in coating systems is a particular advantage in this connection.

It is also possible when they are used as stabilizers in surface coatings to use the additional additives mentioned above, especially antioxidants and light stabilizers.

The compounds I according to the invention are particularly suitable for the stabilization of polystyrene, copolymers of styrene and acrylonitrile (SAN) and acrylonitrile, butadiene and styrene (ABS), polyurethanes, polyamides, polyesters, polyolefins and of surface coatings.

Particularly effective stabilization of polyurethanes is achieved when the polyurethane is stabilized with a mixture of at least one compound I, at least one of the abovementioned antioxidants and at least one of the abovementioned sterically hindered amines.

The esters and amides of aminomethylenecyanoacetic acid I according to the invention are also suitable as sunscreen agents in cosmetic preparations, ie. in particular for the protection of the human skin from the injurious action of light, specifically sunlight, but also artificial light which has a high UV content. Thus, organic materials are to be understood in the widest sense as including the human skin. The cosmetic preparations as such are, of course, also stabilized in order to remain effective for as long as possible.

Accordingly, the present invention also relates to cosmetic preparations which contain from 0.1 to 10% by weight, preferably 1 to 7% by weight, based on the amount of the cosmetic preparation, of one or more esters and amides of aminomethylenecyanoacetic acid I as sunscreen agents. Examples of cosmetic preparations of this type are sunscreen products in liquid, solid or pasty form such as creams, lotions, aerosol foam creams, gels, oils, grease pencils, dusting powders or sprays.

The compounds I are used in the cosmetic preparations in the conventional vehicles or diluents, for example as solution in a cosmetic oil. Examples of conventional cosmetic oil components are liquid paraffin, glyceryl stearate, isopropyl myristate, diisopropyl adipate, cetylstearyl 2-ethylhexanoate, hydrogenated polyisobutene, petrolatum, caprylic/capric acid triglycerides, microcrystalline wax, lanolin and stearic acid. The good solubility of the compounds I in these oil components is a particular advantage.

The compounds I according to the invention are very compatible with the conventional types of plastics and have high solubility in the conventional coating systems and the conventional cosmetic oils. As a rule, they have little or no intrinsic color, are stable and involatile at the conventional processing temperatures for plastics and surface coatings, show only a slight tendency to migrate and, above all, provide long-lasting protection of the organic materials treated with them.

PREPARATION EXAMPLES EXAMPLE 1

21.0 g (0.10 mol) of 1,3-propanediol dicyanoacetate, 19.6 g (0.21 mol) of aniline and 34.1 g (0.23 mol) of triethyl orthoformate in 50 ml of ethylene glycol were heated at 110° C. for 2 h. 38 ml of ethanol were slowly distilled out, during which the temperature rose to 140° C. The mixture was then cooled to 80° C., 100 ml of methanol were added and the mixture was cooled to room temperature. The precipitate was filtered off and washed with methanol and was further purified by boiling with methanol. 27.3 g of product (corresponding to a yield of 66%) of melting point 164°-166° C. were obtained.

The spectroscopic data are shown in Table 1.

EXAMPLES 2 TO 57

The products of cyanoacetic esters II and triethyl orthoformate shown in Table 1 were prepared in a similar manner to Example 1 using the appropriate aromatic or heteroaromatic amines R¹ --NH₂ or R² --NH₂. The melting points and the spectroscopic data of the products are likewise given in Table 1.

                                      TABLE 1                                      __________________________________________________________________________     Structure, melting point and spectroscopic data for the                        aminomethylenecyanoacetic esters I prepared                                     ##STR8##                                (I)                                                                 Melting                                                                             UV data                                     Ex.                                                                               Structure                  point                                                                               (CH.sub.2 Cl.sub.2)                         No.                                                                               R.sup.1                                                                               R.sup.2                                                                               X            [°C.]                                                                        λ.sub.max [nm]                                                               ε                              __________________________________________________________________________     R.sup.1, R.sup.2 = phenyl substituted by the following groups:                  1 H      H      (CH.sub.2).sub.3                                                                            164-66                                                                              321  53800                                   2 4-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                  (CH.sub.2).sub.3                                                                            228-30                                                                              333  79800                                   3 3-CH.sub.3                                                                            3-CH.sub.3                                                                            (CH.sub.2).sub.3                                                                            246-48                                                                              324  34200                                     5-CH.sub.3                                                                            5-CH.sub.3                                                            4 2-CH.sub.3                                                                            2-CH.sub.3                                                                            (CH.sub.2).sub.3                                                                            185  330  46900                                     4-CH.sub. 3                                                                           4-CH.sub.3                                                            5 4-CH.sub.3                                                                            4-CH.sub.3                                                                            (CH.sub.2).sub.3                                                                            186  326  51400                                   6 4-OCH.sub.3                                                                           4-OCH.sub.3                                                                           (CH.sub.2).sub.3                                                                            189  333  45400                                   7 4-OCH.sub.3                                                                           2-CH.sub.3                                                                            (CH.sub.2).sub.3                                                                            175  335  41400                                            4-OCH.sub.3                                                           8 H      H      (CH.sub.2).sub.2                                                                            219  323  51700                                   9 4-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                  (CH.sub.2).sub.2                                                                            246-48                                                                              330                                         10 3-CH.sub.3                                                                            3-CH.sub.3                                                                            (CH.sub.2).sub.2                                                                            225-28                                                                              325  49500                                     5-CH.sub.3                                                                            5-CH.sub.3                                                           11 2-CH.sub.3                                                                            2-CH.sub.3                                                                            (CH.sub.2).sub.2                                                                            222  331  44300                                     4-CH.sub.3                                                                            4-CH.sub.3                                                           12 4-CH.sub.3                                                                            4-CH.sub.3                                                                            (CH.sub.2).sub.2                                                                            260  327  51900                                  13 4-OCH.sub.3                                                                           4-OCH.sub.3                                                                           (CH.sub.2).sub.2                                                                            262  332                                         14 3-CH.sub.3                                                                            2-CH.sub.3                                                                            (CH.sub.2).sub.2                                                                            220  335  37800                                     4-OCH.sub.3                                                                           4-OCH.sub.3                                                          15 H      H      (CH.sub.2).sub.4                                                                            189  321  51200                                  16 4-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                  (CH.sub.2).sub.4                                                                            246  334  64600                                  17 4-CH.sub.3                                                                            4-CH.sub.3                                                                            (CH.sub.2).sub. 4                                                                           212  327  52200                                  18 2-CH.sub.3                                                                            2-CH.sub.3                                                                            (CH.sub.2).sub.4                                                                            226  331  46500                                     4-CH.sub.3                                                                            4-CH.sub.3                                                           19 4-OCH.sub.3                                                                           4-OCH.sub.3                                                                           (CH.sub.2).sub.4                                                                            219  332  45300                                  20 3-CH.sub.3                                                                            3-CH.sub.3                                                                            (CH.sub.2).sub.4                                                                            239  324  52500                                     5-CH.sub.3                                                                            4-CH.sub.3                                                           21 H      H      (CH.sub.2).sub.6                                                                            145  321  54900                                  22 4-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                  (CH.sub.2).sub.6                                                                            232  333  77700                                  23 3-CH.sub.3                                                                            3-CH.sub.3                                                                            (CH.sub.2).sub.6                                                                            188  324  53000                                     5-CH.sub.3                                                                            5-CH.sub.3                                                           24 2-CH.sub.3                                                                            2-CH.sub.3                                                                            (CH.sub.2).sub.6                                                                            223  330  44900                                     4-CH.sub.3                                                                            4-CH.sub.3                                                           25 4-CH.sub.3                                                                            4-CH.sub.3                                                                            (CH.sub.2).sub.6                                                                            193  323  50700                                  26 4-OCH.sub.3                                                                           4-OCH.sub.3                                                                           (CH.sub.2).sub.6                                                                            163  331  45800                                  27 4-Cl   4-Cl   (CH.sub.2).sub.6                                                                            191  324  46200                                  28 4-CN   4-CN   (CH.sub.2).sub.6                                                                            268-71                                                                              330                                         29 H      H                                                                                      ##STR9##    255-64                                                                              324  62700                                  30 4-OCH.sub.3                                                                           4-OCH.sub.3                                                                            ##STR10##   265  333  44800                                  31 3-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                   ##STR11##   239-47                                                                              336  81700                                  32 3-CH.sub.3                                                                            3-CH.sub.3                                                                             ##STR12##   259-64                                                                              325  51200                                     5-CH.sub.3                                                                            5-CH.sub.3                                                           33 2-CH.sub.3                                                                            2-CH.sub.3                                                                             ##STR13##   247  332  48400                                  34 4-CH.sub.3                                                                            4-CH.sub.3                                                                             ##STR14##   280  326  53500                                  35 5-CN   4-CN                                                                                   ##STR15##   310  334  61700                                  36 H      H                                                                                      ##STR16##   113  320  49700                                  37 H      H      CH.sub.2 CHCHCH.sub.2                                                                       139  322  54400                                  38 4-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                  CH.sub.2 CHCHCH.sub.2                                                                       183  332  77400                                  39 3-CH.sub.3                                                                            3-CH.sub.3                                                                            CH.sub.2 CHCHCH.sub.2                                                                       137  325  52400                                     5-CH.sub.3                                                                            5-CH.sub.3                                                           40 2-CH.sub.3                                                                            2-CH.sub.3                                                                            CH.sub.2 CHCHCH.sub.2                                                                       206  330  48600                                     4-CH.sub.3                                                                            4-CH.sub.3                                                           41 4-CH.sub.3                                                                            4-CH.sub.3                                                                            CH.sub.2 CHCHCH.sub.2                                                                       184  326  52700                                  42 4-Cl   4-Cl   CH.sub.2 CHCHCH.sub.2                                                                       213  326  59700                                  43 H      H      CH.sub.2 CCCH.sub.2                                                                         185  322  52400                                  44 4-COOC.sub.2 H.sub.5                                                                  4-COOC.sub.2 H.sub.5                                                                  CH.sub.2 CCCH.sub.2                                                                         242  332  79100                                  45 3-CH.sub.3                                                                            3-CH.sub.3                                                                            CH.sub.2 CCCH.sub.2                                                                         239  324                                            5-CH.sub.3                                                                            5-CH.sub.3                                                           46 2-CH.sub.3                                                                            2-CH.sub.3                                                                            CH.sub.2 CCCH.sub.2                                                                         249  331  45000                                     4-CH.sub.3                                                                            4-CH.sub.3                                                           47 4-CH.sub.3                                                                            4-CH.sub.3                                                                            CH.sub.2 CCCH.sub.2                                                                         244  327  50500                                  48 4-Cl   4-Cl   CH.sub.2 CCCH.sub.2                                                                         243  326  54600                                  49 2-CH.sub. 3                                                                           2-CH.sub.3                                                                            (CH.sub.2).sub.6                                                                            205  328  48500                                  50 H      H                                                                                      ##STR17##   257  320                                         51 4-COOC.sub.2 H.sub.5                                                                  4 -COOC.sub.2 H.sub.5                                                                  ##STR18##   263  329                                         52 2-OCH.sub.3                                                                           2-OCH.sub.3                                                                           (CH.sub.2)6  242-45                                                                              348                                            4-OCH.sub.3                                                                           4-OCH.sub.3                                                          53 H      H      (CH.sub.2 CH.sub.2 O).sub.4,2 CH.sub.2 CH.sub.2                                             (resin)                                                                             321                                         R.sup.1 R.sup.2 = Hetaryl                                                      54 3-Pyridinyl   (CH.sub.2).sub.2                                                                            200  318                                         55 4,6-Dimethyl-2-pyrimidinyl                                                                   (CH.sub.2).sub.2                                                                            228  316  63400                                  56 4,6-Dimethyl-2-pyrimidinyl                                                                    ##STR19##   262-65                                                                              315  71700                                  57 4,6-Dimethyl-2-pyrimidinyl                                                                   (CH.sub.2).sub.4                                                                            203  314  64800                                  __________________________________________________________________________      Note: The double bond in 1,4but-2-enylene for X in Examples Nos. 37 to 42      is cis.                                                                  

EXAMPLES 58 TO 80

In a similar manner to Example 1 and using the appropriate aromatic or heteroaromatic amines R¹ --NH₂ or R² --NH₂, the products listed in Table 2 were prepared from appropriate biscyanoacetamides II and triethyl orthoformate. The melting points and spectroscopic data of the products are likewise indicated in Table 2.

                                      TABLE 2                                      __________________________________________________________________________     Structure, melting point and spectroscopic data                                for the aminomethylenecyanoicetamides I prepared                                ##STR20##                              (I)                                                                 Melting                                                                             UV data                                      Ex.                                                                               Structure                 point                                                                               (CH.sub.2 Cl.sub.2)                          No.                                                                               R.sup.1 R.sup.2                                                                             X            [°C.]                                                                        λ.sub.max [nm]                                                               ε                               __________________________________________________________________________     58 Phenyl       (CH.sub.2).sub.6                                                                            202  323  57500                                   59 3,5-Dimethylphenyl                                                                          (CH.sub.2).sub.6                                                                            233  326  57800                                   60 4-Ethoxycarbonyl-                                                                           (CH.sub.2).sub.6                                                  phenyl                                                                      61 4-Methoxyphenyl                                                                             (CH.sub.2).sub.6                                                                            215  332  48600                                   62 4-Methylphenyl                                                                              (CH.sub.2).sub.6                                                                            210  326  54100                                   63 2,4-Dimethylphenyl                                                                          (CH.sub.2).sub.6                                                                            198  330  51000                                   64 Phenyl                                                                                       ##STR21##   306  327  53300                                   65 4-Methylphenyl                                                                               ##STR22##   293  329  60100                                   66 4-Methoxyphenyl                                                                              ##STR23##   295  334  50500                                   67 3,5-Dimethylphenyl                                                                           ##STR24##   265  327  49400                                   68 Phenyl                                                                                       ##STR25##   218  324  54000                                   69 4-Ethoxycarbonyl-phenyl                                                                      ##STR26##   271  337  83600                                   70 4-Methoxyphenyl                                                                              ##STR27##   246  332  46300                                   71 Phenyl       (CH.sub.2).sub.2                                                                            268  325  56100                                   72 4-Ethoxycarbonyl-phenyl                                                                     (CH.sub.2).sub.2                                                                            235  337  73200                                   73 3,5-Dimethylphenyl                                                                          (CH.sub.2).sub.2                                                                            261  327  56300                                   74 4-Methylphenyl                                                                              (CH.sub.2).sub.2                                                                            263  328  57200                                   75 4-Methoxyphenyl                                                                             (CH.sub.2).sub.2                                                                            244  333  --                                      76 4,6-Dimethyl-2-pyrimidinyl                                                                  (CH.sub.2).sub.7                                                                            263  315  71500                                   77 4,6-Dimethyl-2-pyrimidinyl                                                                   ##STR28##   311  315  --                                      78 Phenyl       (CH.sub.2).sub.3                                                                            203  324  58400                                   79 4-Methylphenyl                                                                              (CH.sub.2).sub.3                                                                            231  328  58600                                   80 4-Methoxyphenyl                                                                             (CH.sub.2).sub.3                                                                            191  333  51000                                   __________________________________________________________________________

USE EXAMPLES

ABS specimens for the light exposure tests were produced by dissolving 0.5% by weight of the sterically hindered amine of the formula IV and 0.5% by weight of the UV absorber according to the invention which is indicated in Table 3 in ABS (Terluran 967 K, unpigmented) by a single extrusion at a melt temperature of 250° C., and injection molding the resulting granules at 260° C. to give specimens 2 mm thick.

The specimens were tested for resistance to light and weathering in a Xenotest• 1200 accelerated weathering tester.

The yellowness index (YI, Annual Book of ASTM Standards D 1925-70 (Reapproved 1977)) is a measure of the photooxidative breakdown of the polymer during the weathering time.

The stabilizer mixtures used, and the results of the light exposure test are detailed in Table 3.

                  TABLE 3                                                          ______________________________________                                         YI values for ABS specimens                                                    Stabilzer                  YI                                                  mixture                    after 500 h                                         ______________________________________                                         According to the invention:                                                    0.5% by wt IV + 0.5% by wt prod. of Ex. 6                                                                 28                                                  0.5% by wt IV + 0.5% by wt prod. of Ex. 15                                                                27                                                  0.5% by wt IV + 0.5% by wt prod. of Ex. 17                                                                28                                                  Comparative:                                                                   No stabiliser              52                                                  0.5% by wt IV + 0.5% by wt IIIa                                                                           34                                                  IIIa:                                                                                ##STR29##                disclosed in US-A 3 079 366                     IV:                                                                                  ##STR30##                                                                ______________________________________                                     

We claim:
 1. An ester or amide of aminomethylenecyanoacetic acid of the formula I ##STR31## where R¹ and R² are each, independently of one another, phenyl, naphthyl, biphenylyl, pyridine or pyrimidine, it being possible for these radicals to be substituted by one to three C₁ -C₁₂ -alkyl groups, C₁ -C₁₂ -alkoxy groups, halogen atoms,cyano groups, hydroxyl groups or groups of the formulae COOR³, COR³, CONHR³, OCOR³ or NHCOR³, and whereR³ is C₁ -C₁₂ -alkyl, C₅ -C₈ -cycloalkyl or phenyl, X is C₂ -C₃₀ -alkylene which can be interrupted by non-adjacent oxygens, or is C₄ -C₁₂ -alkenylene or C₄ -C₁₂ -alkynylene where the unsaturated bonds are not adjacent to the ester oxygens, or is C₅ -C₈ -cycloalkylene or phenylene, and Y is O or NH.
 2. An ester or amide of aminomethylenecyanoacetic acid I as claimed in claim 1, where R¹ and R² are each, independently of one another, phenyl which can be substituted by one or two C₁ -C₁₂ -alkyl groups, C₁ -C₁₂ -alkoxy groups, chlorine atoms, cyano groups, hydroxyl groups or groups of the formula COOR³ or pyridinyl or 2-pyrimidinyl, each of which can be substituted by one or two C₁ -C₄ -alkyl groups.
 3. An ester or amide of aminomethylenecyanoacetic acid I as claimed in claim 1 or 2, where X is C₂ -C₁₂ -alkylene, --(CH₂ CH₂ O)_(n) --CH₂ CH₂ -- or ##STR32## where n is 1 to 9, 1,4-but-2-enylene, 1,4-but-2-ynylene, C₆ -C₈ -cycloalkylene or phenylene.
 4. The ester or amide of claim 1, wherein R¹ and R² are each independently selected from the group consisting of phenyl, naphthyl, biphenylyl, pyridine and pyrimidine each of which are unsubstituted.
 5. The ester or amide of claim 4, wherein R¹ and R² are each independently phenyl, pyridyl or pyrimidyl.
 6. The ester or amide of claim 4, wherein R¹ and R² are the same.
 7. A cosmetic preparation containing from 0.1 to 10% by weight, based on the amount of the cosmetic preparation, of one or more esters or amides of aminomethylenecyanoacetic acids I as claimed in claim 1, 2, 3 or
 4. 8. A method for protecting human skin from the action of light, which comprises applying to said human skin a cosmetic preparation comprising one or more esters or amides of aminomethylenecyanoacetic acid I as claimed in claim 1, 2, 3 or 4 in an amount effective as a sunscreen agent. 